Acid dyestuffs of the anthraquinone series



Patented July 7, 1936 UNITED STATES 2,046,835 PATENT OFFICE Delaware NoDrawing. Application January 23, 1935, Serial No. 3,186. In GermanyFebruary 1, 1934 9 Claims.

The present invention relates to acid dyestuffs of the anthraquinoneseries.

We have found that valuable acid dyestuffs of the anthraquinone seriesare obtained by preparing compounds having the formula:

11% O NH O ITIH in which R1 and R2 are identical or difierent arylradicles, one X is a carboxylic acid group esterified with an aliphaticalcohol of low molecular weight, the other X a hydrogen atom, and whichcontain one or more sulfonic acid groups in the anthraquinone radicleand/or in the substituents. The dyestuffs are especially suitable fordyeing wool and are distinguished by excellent properties as regardsfastness and especially by a good levelling power.

The following examples will further illustrate how the said inventionmay be carried out in practice but the invention is not restricted tothese examples. The parts are by weight.

Example 1 10 parts of 1,4-dichloroanthraquinone-2-carboxylic acid methylester (obtainable for example froml-amino-2-methyl-4-chl0roanthraquinone by diazotization, reaction of theresulting diazo compound with cuprous chloride according to Sandmeyer,oxidation of the resulting lA-dichlor-2-methylanthraquinone withpyrolusite in sulfuric acid and esterification), 100 parts ofpara-toluidine, 10 parts of anhydrous potassium acetate and 0.1 part ofcopper acetate are heated at 150 C. until no further change in the colorof the reaction mixture towards green takes place. The whole is thenallowed to cool to 100 0., diluted with methanol and the deposited greencrystals are separated. v

5 parts of the resulting 1,4-di-para-toluidinoanthraquinone-Z-carboxylicacid methyl ester are dissolved in 50 parts of sulfuric acid monohydrateand treated at about 10 C. with fuming sulfuric acid containing 23 percent of $03 until a sample of the product when Worked up is completelysoluble in water. The whole is then poured on to ice and the dyestufiformed is salted out in the usual manner.

The dyestuff dyes wool clear yellowish green shades of excellentproperties as regards fastness from a weakly acid bath.

If the para-toluidine be replaced by aniline and the same procedure befollowed, a dyestuff yielding somewhat more bluish dyeings is obtained.If the treatment with fuming sulfuric acid is carried out under morevigorous conditions as regards the strength of the fuming sulfuric acidand the reaction period, a dyestuff containing most probably twosulfonic acid groups in each of the anilido groups is obtained.

Example 2 10 parts of 1,4-dichloroanthraquinone-2-carboxylic acid methylester (prepared as described in Example 1), 100 parts ofpara-cyclohexylaniline, 8 parts of anhydrous sodium acetate and 0.1 partof copper acetate are heated at 150 C. until the color of a samplewithdrawn and dissolved in 1 pyridine no longer changes. The whole isthen allowed to cool to 100 C., diluted with methanol and the crystalsof 1,4-di-(para-cyclohexylanilino) -anthraquinone-2-carboxylic acidmethyl ester obtained after cooling are separated.

5 parts of the resulting reaction product are dissolved in 50 parts ofsulfuric acid monohydrate and treated at about 10 C. with fumingsulfuric acid containing 23 per cent of S03 until a sample withdrawn andworked up is completely soluble in water. The whole is then poured on toice and the dyestuff is salted out in the usual manner.

The dyestuff dyes wool clear yellowish green shades of excellentfastness properties from a weakly acid bath.

Example 3 A mixture of 10 parts of 1,4-dichloranthraquinone-Z-carboxylicacid methyl ester, 20 parts of aniline and 3 parts of anhydrous sodiumacetate is heated while stirring at from to C. until the color of themelt no longer changes. After cooling, the melt is diluted with methanoland the crystals deposited are isolated in the usual manner.

A mixture of 5 parts of the l-anilino-4-chloranthraquinone-Z-carboxylicacid methyl ester thus obtained, 1.25 parts of anhydrous sodium acetate,25 parts of para-toluidine and 0.2 part of copper acetate is heated atfrom to C. until the color of the melt no longer changes. After dilutingthe melt with methanol, the green needles formed are isolated in theusual manner.

5 parts of the 1-anilido-4-para-toluidinoanthraquinone-2-carboxy1ic acidmethyl ester are introduced at from 5 to 8 0. into 50 parts of sulfuricacid monohydrate. As soon as the initial compound has been completelydissolved fuming sulfuric acid containing 23 per cent of S03 is addeduntil a sample withdrawn has become readily soluble in Water. Themixture is then poured on to ice and the dyestufi formed is salted outwith common salt. It dyes wool green shades of good fastness propertiesalso from weakly acid baths.

Example 4 A mixture of 50 parts of 1,4-dichloranthraquinone-Z-carboxylicacid methyl ester, 150 parts of para-toluidine and 12.5 parts ofanhydrous so dium acetate is heated at C. while stirring until the colorof the melt no longer changes. It is then diluted with methanol and theviolet crystals formed are isolated in the usual manner.

A mixture of 32 parts of the 1-toluidino-4-chloranthraquinone-2-carboxylic acid methyl ester, 8 parts of anhydroussodium acetate, 160 parts of aniline and 1.6 parts of copper acetate isheated at from to C. until the color of the melt no longer changes.After adding methanol, the green crystals formed are isolated in theusual manner.

10 parts of the 1-para-toluidino-4-anilinoanthraquinone-2-carboxylicacid methyl ester are dissolved at about 10 C. in 100 parts of fumingsulfuric acid containing 5 per cent of S03. The solution is stirred atthe said temperature until a sample withdrawn has become readily solublein Water. The solution is then poured on to ice and the dyestuff formedis salted out with common salt. It dyes wool yellowish green shades froma weakly acid bath.

ExampZe 5 A mixture of 10 parts of 1,4-dichloranthraquinone-G-carboxylicacid methyl ester (obtainable by heating 1.4 dichloranthraquinone 6carboxylic acid with methanol in the presence of sulfuric acid), 150parts of para-toluidine and little copper acetate is heated in thepresence of anhydrous potassium acetate at about C. until a samplewithdrawn is free from chlorine. After adding 150 parts of butanol, thecrystals formed are isolated in the usual manner.

10 parts of the 1,4-di-para-toluidinoanthraquinone-G-carboxylic acidmethyl ester are dissolved at between 5 andl0 C. in 100 parts of fumingsulfuric acid containing 5 per cent of S03. Then fuming sulfuric acidcontaining 23 per cent of S03 is added until a sample withdrawn hasbecome readily soluble in cold water. The mixture is then poured into1000 parts of ice-cold water while stirring. The precipitate formedhereby is filtered oif by suction and dissolved in about 200 parts ofhot water. By salting out with common salt a dyestufi is obtained whichdyes wool green shades of excellent fastness properties.

Instead of the methyl ester the ethyl ester of1,4-dichloranthraquinone-6-carboxylic acid ma be employed as startingmaterial.

Example 6 A mixture of 33 parts of 1,4-dichloranthraquinone-G-carboxylicacid methyl ester, 300 parts of para-cyclohexyl-analine, 30 parts ofanhydrous potassium acetate and 0.3 part of copper acetate is heated atfrom 140 to C. until a sample withdrawn is free from chlorine. Themixture is then cooled to 120 C. and then 600 parts of hot butanol areadded thereto. It is stirred until it has become cold.1,4-di-para-cyclohexylanilinoanthraquinone-G-carboxylic acid methylester separates in the form of green leaflets which are isolated in theusual manner.

10 parts of the ester thus obtained are dissolved at about 5 C. in partsof fuming sulfuric acid containing 10 per cent of S03. The solution isthen stirred until a sample withdrawn has become readily soluble inwater. It is then poured into about 1500 parts of ice-cold water. Theprecipitate formed is then recrystallized from hot water while adding asolution of common salt. The dyestufi obtained dyes wool from acid bathsgreen shades of excellent fastness properties.

Example 7 10 parts of 1,4-di-para-toluidinoanthraquinone-fi-carboxylicacid are dissolved at 20 C. in 75 parts of fuming sulfuric acidcontaining 5 per cent of S03. Fuming sulfuric acid containing 23 percent of S03 is then added to the solution until a sample withdrawn hasbecome readily soluble in water. The mixture is then poured into 500parts of methanol and the whole is heated to boiling until the formationof the methyl ester is completed. The mixture is then poured into anice-cold dilute solution of common salt while stirring. The precipitateformed is then filtered off by suction, washed with dilute solution ofcommon salt until neutral and recrystallized from hot water while addinga solution of common salt; The dyestuff thus obtained is practicallyidentical to that prepared according to Example 5.

What we claim is:

1. Acid dyestuffs of the anthraquinone series corresponding to thegeneral formula:

'11 M 1 A x (SO3H),.

l o IIIH in which R1 and R2 stand for aryl radicles of the benzeneseries, one X for a carboxylic acid group esterified With an aliphaticalcohol of low molecular weight, the other X for hydrogen and n for awhole number up to 4.

2. Acid dyestuffs of the anthraquinone series corresponding to thegeneral formula:

R2 in which R1 and R2 stand for equal aryl radicles of the benzeneseries, one X for a carboxylic acid group esterified with an aliphaticalcohol of low molecular weight, the other X for hydrogen and nfc-r awhole number up to 4.

3. Acid dyestuffs of the anthraquinone series in which R1 and R2 standfor different aryl radicles of the benzene series, one X for acarboxylic acid group esterified with an aliphatic alcohol of lowmolecular weight, the other X for hydrogen andn for a whole number up to4.

4. Acid dyestuffs of the anthraquinone series 8. The acid dyestuif ofthe anthraquinone corresponding to the general formula: series havingthe formula:

I? H: 0 NH C II I mo \CH: 0 000113 aH)- HA) (3H1 Y CH I SOaH R2 in whichR1 and R2 stand for aryl radicles of the benzene series and n for awhole number up to 4. 0 NH 5. Acid dyestuffs of the anthraquinone seriescorresponding to the general formula:

Hie-000 Y -(SOaH)n a Y s0,11

I l o IITH in which R1 and R2 stand for aryl radicles of the H benzeneseries and n for a whole number up to 4. I 6. Acid dyestuffs of theanthraquinone series corresponding to the general formula: 0

R1 H, 0 9. The acid dyestufi of the anthraquinone II I series having theformula: X CH:

Y -SO:H

0 ITTH R2 0 NE in which R1 and R2 stand for aryl radicles of the II Ibenzene series each of which contains up to two sulfonic acid groups,one X for a carboxylic acid group esterified with an aliphatic alcoholof 10W H C OOO molecular weight and the other X for hydrogen. l

'7. The acid dyestuff of the anthraquinone 1 NH series having theformula:

-s0=H mc \(IJHZ H2O CH2 I PAUL NAWIASKY.

ROBERT ZELL. I WALTHER KUEHNE.

0 I lH II CO0CHa II 0 NH SO3H f5 Hz? CH2 H2O CH2

